Recently, a metric named Age of Information (AoI) has been proposed [1]} as a measure of the freshness of the information update. In this setting, a sensor monitoring a system generates time stamped status update and sends it to the sink over a network. At time \(t\) , if the latest monitoring information available to the sink node comes from a packet whose time-stamped generation instant was \(t^{\prime }\) , then the AoI at the sink node is computed as \((t-t’)\) . Thus, AoI has emerged as an alternative metric to mean delay [2]}.
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